1. Technical Field
The disclosure generally relates to circuit boards, and particularly to a multilayer circuit board with an even current distribution and relatively higher current transmission efficiency.
2. Description of Related Art
A typical circuit board usually includes a plurality of conductive layers made of copper foil and a plurality of vias defined in the conductive layer to electrically connect the conductive layers. A voltage regulator module can provide electrically power to the circuit board by a plurality of power supply elements such as output choke coils. The power supply elements outputs current to an electronic element, such as a processor mounted to the circuit board by the vias and the conductive layers.
However, when the distribution of the vias arranged on the circuit board is irregular, current flowing through each via is different, which causes the current distribution of the circuit board uneven. Thus, the circuit board may be damaged by overheating in the areas with more current and have a shorter lifespan.
In addition, because the upper conductive layers transmits higher current than the lower conductive layers, the total number of the vias arranged on the circuit board needs to be enough to enable each conductive layer to transmit a even current, which may increase impedance of the circuit board and lead to a lower current transmission efficiency.
Therefore, there is room for improvement within the art.